Introduction Flashcards
What are the functions of the kidney
Regulate water, electrolytes, arterial blood pressure (via blood vol. and renin-angiotensin).
Excrete metabolic waste, foreign substances.
Acid base reg.
Reg. RBC production.
Vit D production.
Gluconeogenesis during long fasting.
lumen of nephron
inside of the tube
luminal side of tubular cell
side facing lumen of the cell surrounding the tube
apical side of tubular cell
side facing apex of the cell surrounding the tube
basolateral side of tubular cells
sides of tubular cells facing intersitial fluid
what happens in the proximal convoluted tubule
67% of H2O, Na< K, Cl and nearly all glucose and AA reabsored here
what is thick ascending limb sometimes called
diluting segement
what happens in macular densa
Feedback to juxtaglomerular apparatus. Vasodilates/constricts afferent art. to maintain constant GFR and renal blood flow despite changes in systemic art. BP.
what happens in the distal convoluted tubule
Reaborbs Na/K/Cl but impermeable to H20 and urea = also diluting segment.
what happens in cortical collectin duct
Principal cell, reabsorbs Na and secretes K. Intercalating cell reabsorbs K and secretes H. Whole segment responsive to ADH.
how is protein reabsorbed in the proximal tubule
Peptidases in lumen of proximal conv. Tubule (apical surface) break peptides into AAs which are
reabsorbed. Larger proteins endocytosed, lysosomic enzymes degrade to AAs which leave tubular cell
across basolateral memb. Normally all protein reabsorbed, but the mechanism for reabsorption can
become saturated and then proteinuria.
Where does ADH act in the kidney
collecting duct
what happens when you increase ADH
reabsorb more water, conc urine
which nerve has parasympathetic innervation
S2, 3, 4 (pelvic nerves)
what do SS2,3,4 do
contract bladder
what neveres have symphatic innervation
L1,2,3 (hypogastric n)
what nerves have coluntary moto input
S2,3,4 pudendal n
vesicoureteral reflux
Backward flow of urine into ureters during bladder contraction. Enlarges ureters. Increases chances of kidney infection.
ureterorenal reflex
Stone blocks ureter, sensory afferents from ureter cause reflex and constriction of renal arterioles. This decreases fluid flow from that kidney.
micturition reflex
Initiated by bladder stretch receptors. Pelvic nerves carry sensory to sacral segments of cord, parasymps back tell detrusor to tighten and pressure spikes. As bladder fills, reflex gets stronger and occurs at faster rate. Is autonomic spinal cord reflex, can be inhibited/facilitated by the brain. Cortical and suprapontine centers in brain can inhibit this reflex.
sympathetic storage reflex
initiated as bladder distends and afferent activity travels in pelvic nerves to spinal cord. Firing from symp L1,2,3 initiated – decrease parasymp inputs to bladder.
somatic storage reflex (guarding or continence reflex)
caused by sudden increase in bladder pressure. Pelvic N to sacral spinal cord -> efferent somatic neurons in nucleus of Onuf are activated. Motor neurons to ext. sphincter. Inhibited during micturition so external sphincter will relax.
atonic bladder
no micturition reflex
bladder does not empty and therefore leaks, causes overflow incontinence
what can cause atonic bladder
crush injury to sacral region of spinal cord, tertiary syphilis
what is automatic bladder
typical micturition can occur, but brain isn’t in control of the reflex for reflex empty eventually becomes automatic. overfill incontinence
what can causes automatic bladder
spinal cord damage above sacral region
what is the immediate effect on the bladder of spinal cord damage above sacral region
overflow incontinence
what can cause uninhibited neurogenic bladder
partial damage to spinal cord or brainstem
what is the syptoms of uninhibited neurogenic bladder
uncontrollable mictrutiion, even a small amount of urine in bladder causes you to pee
